Pb0.92La0.08(Zr0.65Ti0.35) o.98O3 (PLZT) nanosized powder was prepared from the corresponding nitrate alnd H2O2 by thermal decomposition of the peroxide. FT-IR, DTA-TG, XRD, TEM, and chemical analyses indicated that: ...Pb0.92La0.08(Zr0.65Ti0.35) o.98O3 (PLZT) nanosized powder was prepared from the corresponding nitrate alnd H2O2 by thermal decomposition of the peroxide. FT-IR, DTA-TG, XRD, TEM, and chemical analyses indicated that: (l) Peroxide precursor of PLZT was composed of Pbo.92La0.08 (Zr0.65Ti0.35)0.98O2 (O2) 3H2O; (2) PLZT started to form at 5500C, but PbO and PbZro3 still existed; (3) homogeneous tetragonal crystals of PLZT were formed at 7000C, with average particle diameter Of 22nm; (4) the sizes of the crystals increased with increasing calcination temperatures, crystals of PLZT were formed at 8500C with average particle diameter of 56nm.展开更多
Aligned carbon nanotubes(CNTs)were synthesized by nebulized spray pyrolysis of solutions of organometallics in carbon precursor solvents.Four types of straight-chained alkanes including n-pentane,n-hexane,n-heptane an...Aligned carbon nanotubes(CNTs)were synthesized by nebulized spray pyrolysis of solutions of organometallics in carbon precursor solvents.Four types of straight-chained alkanes including n-pentane,n-hexane,n-heptane and n-octane were used as precursor solvents for synthesis of aligned CNTs.The results from scanning electron microscopy,transmission electron microscopy and Raman spectroscopy show that the CNTs obtained from them have different diameters and degrees of graphitization. It is found that the n-heptane is the most suitable for the growth of aligned CNTs with high quality and yield.The thermodynamic properties of precursory carbon sources such as boiling point and formation enthalpy are considered to play a decisive role in the synthesis of CNTs.It will be very helpful for the controllable preparation of aligned CNTs at relatively low cost.展开更多
文摘Pb0.92La0.08(Zr0.65Ti0.35) o.98O3 (PLZT) nanosized powder was prepared from the corresponding nitrate alnd H2O2 by thermal decomposition of the peroxide. FT-IR, DTA-TG, XRD, TEM, and chemical analyses indicated that: (l) Peroxide precursor of PLZT was composed of Pbo.92La0.08 (Zr0.65Ti0.35)0.98O2 (O2) 3H2O; (2) PLZT started to form at 5500C, but PbO and PbZro3 still existed; (3) homogeneous tetragonal crystals of PLZT were formed at 7000C, with average particle diameter Of 22nm; (4) the sizes of the crystals increased with increasing calcination temperatures, crystals of PLZT were formed at 8500C with average particle diameter of 56nm.
基金Projects(50772033, 50972043) supported by the National Natural Science Foundation of ChinaProject(2007FJ3003) supported by the Natural Science Foundation of Hunan Province, China
文摘Aligned carbon nanotubes(CNTs)were synthesized by nebulized spray pyrolysis of solutions of organometallics in carbon precursor solvents.Four types of straight-chained alkanes including n-pentane,n-hexane,n-heptane and n-octane were used as precursor solvents for synthesis of aligned CNTs.The results from scanning electron microscopy,transmission electron microscopy and Raman spectroscopy show that the CNTs obtained from them have different diameters and degrees of graphitization. It is found that the n-heptane is the most suitable for the growth of aligned CNTs with high quality and yield.The thermodynamic properties of precursory carbon sources such as boiling point and formation enthalpy are considered to play a decisive role in the synthesis of CNTs.It will be very helpful for the controllable preparation of aligned CNTs at relatively low cost.
